The present invention relates, in general, to semiconductor devices, and more specifically, to semiconductor devices with improved heat dissipation capabilities.
Semiconductor devices inherently generate heat during operation. The heat must be dissipated so that the semiconductor device is maintained at an acceptable operating temperature. Many modern semiconductor devices have increased power dissipation which is directly related to the amount of heat generated. For example, high frequency analog amplifiers used in modern telecommunication circuits tend to be very high power devices. Similarly, the powerful microprocessors emerging in the industry tend to be high power and generate a great deal of heat.
Additional heat dissipation issues arise in the case where the semiconductor device is configured as a "flip-chip". In flip-chip configuration, the surface of a semiconductor die which has an electronic device formed in it directly opposes a die attach substrate. The semiconductor die is typically attached to the die attach substrate only by conductive bumps which lead to the bonding pads of the semiconductor die. Typically, electrical traces printed on the die attach substrate lead from the bumps to provide interconnection to other circuit components.
The described flip-chip configuration gives rise to heat dissipation problems because most of the heat generated by a semiconductor device is generated at the die surface containing the electronic device. In the flip-chip configuration, this surface is sandwiched against a die attach substrate which is typically a ceramic insulator that is a relatively poor heatsink. The majority of the heat generated by a flip-chip is conducted away from the flip-chip only through the conductive bumps and associated traces. The conductive bumps provide an extremely small surface area through which the heat must be dissipated. This results in undesirable localized hot points and heat gradients.
What is needed is a semiconductor device with improved heat dissipation capability. A configuration would be desirable wherein a much greater surface area is utilized for conducting heat away from the surface of a semiconductor die. With regard to a flip-chip configuration, it would be desirable to efficiently couple the semiconductor die to the die attach substrate for maximized heat transfer.